1.Be sure where you are planning to do business from is approved by your zoning board as commercial...to "manufacture". If its from your house, you will need a variance first (in writing) before the feds issue a license for that location.
2.Apply for your EIN(Employer Identification Number) with your state gov't when you register your business for tax purposes
3. Apply for a type 07 FFL($150). This will allow you to do everything an 01 can do, but you get to manufacture with it. Its nice just to have so you can do non NFA stuff also.The feds will come in to do a simple interview and explain everything you need to know after you apply for it
4. After you get your 07 FFL, Simply pay the $500(per year) to the NFA branchfor the "special tax stamp" which will allow you to manufacture all the good NFA stuff.
4. There are alot of mixed feelings about this next one, but I will mention it anyway. Register with the State Dept. and pay $600 a year to them. Its a sore subject and alot of guys dont bother with it. But you never heard that from me.
Do yourself a favor and buy the "Machine Gun Dealers Bible" that was put together specifically for what you have in mind. It explains it all in detailed, easy to understand language. It does not leave anything out. I think you can get it from the Small Arms Review web site here .....
http://www.smallarmsreview.com/bible.htm
Its not as hard or complicated as it may sound. You just dont want to get backed into a corner from ignorance of the law. I hope this helps you get started. You can call me for info on this because I really hate to type
Brian 585-638-8232